The invention relates generally to welding systems. Specifically, the embodiments described herein relate to detecting non-operating silicon-controlled rectifiers (SCRs) in power supplies for welding systems.
Many types of welding operations require significant amounts of power. Welding systems may use a high current or high voltage input signal to generate large welding currents and voltages suitable for the welding operation. In particular, welding systems may use isolated alternating current (AC) input signal, and may convert the input signals into direct current (DC) signals suitable for operation.
To perform this power conversion, power conversion circuitry for the welding system may include one or more SCRs. However, if at least one of the SCRs becomes non-operating (i.e., non-firing, open circuit, or shorted), then the welding system should be removed from operation.
As such, the welding system often includes circuitry or control logic that detects shorted SCRs. For instance, the welding system may include control logic that test the circuitry containing the SCRs using a variety of test signals, and may compare the outputted signals to target signals. This process may be performed periodically or based on an event, such as start-up of the welding system. However, it would be beneficial to improve the process for detecting shorted SCRs. Further, it would be desirable to detect any type of non-operating SCRs (i.e., non-firing, open, and shorted SCRs).